The NSW government has provided $500,000 for the work, which involves widening and filling the embankment next to the Forest Road turning lane and building a new off-road path for about 200 metres.

A concrete retaining wall will be built and a section of the existing wire rope safety barrier will be replaced with guardrail.

Safety signs and bicycle holding rails will also be installed.

Work started on Monday and will be carried out between 7am and 6pm on weekdays until early November.

The southbound turning lane at Forest Road will be closed from Wednesday, October 8 until early November between 7am and 3pm on weekdays. 

Traffic control will guide motorists turning left into Forest Road.

The northbound turning lane at BTU Road will be closed between 9am and 6pm for three days during the final stage of work and traffic control will be in place to guide motorists turning left into BTU Road.

For the latest traffic information, visit www.livetraffic.com, download the Live Traffic app or call the Transport Management Centre on 132 701.